Weak orogenic lithosphere guides the pattern of plume-triggered supercontinent break-up

Dang, Zhuo; Zhang, Nan; Li, Zheng‐Xiang; Huang, Chuan Zhen; Spencer, Christopher J.; Liu, Yebo

doi:10.1038/s43247-020-00052-z

Cited by 31 publications

(10 citation statements)

References 101 publications

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“…It was found that plume erosion decreases lithospheric strength and controls the timing or even occurrence of continental break-up. Plumes can help to trigger final continental break-up by weakening lithosphere where it is already thinned, as hot plume material feeds into existing rifts and sutures, and plumeinduced melts can thin even thick cratonic lithosphere and facilitate rifting 292,293 .…”

Section: Breaking Up Continents and Initiating Subductionmentioning

confidence: 99%

Mantle plumes and their role in Earth processes

Koppers

Becker

Jackson

et al. 2021

Nat Rev Earth Environ

127

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The existence of mantle plumes was first proposed in the 1970s to explain intra-plate, hotspot volcanism, yet owing to difficulties in resolving mantle upwellings with geophysical images and discrepancies in interpretations of geochemical and geochronological data, the origin, dynamics and composition of plumes and their links to plate tectonics are still contested. In this Review, we discuss progress in seismic imaging, mantle flow modelling, plate tectonic reconstructions and geochemical analyses that have led to a more detailed understanding of mantle plumes. Observations suggest plumes could be both thermal and chemical in nature, can attain complex and broad shapes, and that more than 18 plumes might be rooted in regions of the lowermost mantle. The case for a deep mantle origin is strengthened by the geochemistry of hotspot volcanoes that provide evidence for entrainment of deeply recycled subducted components, primordial m an tle domains and, potentially, materials from Earth's core. Deep mantle plumes often appear deflected by large-scale mantle flow, resulting in hotspot motions required to resolve past tectonic plate motions. Future research requires improvements in resolution of seismic tomography to better visualize deep mantle plume structures at smaller than 100-km scales. Concerted multi-proxy geochemical and dating efforts are also needed to better resolve spatiotemporal and chemical evolutions of long-lived mantle plumes.

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Section: Breaking Up Continents and Initiating Subductionmentioning

confidence: 99%

Mantle plumes and their role in Earth processes

Koppers

Becker

Jackson

et al. 2021

Nat Rev Earth Environ

127

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“…Such weak zones, or damage zones, significantly differ from the surrounding lithosphere, for example, compositionally or mechanically, for example, due to failed rifts. Weak zones thus represent rheological “memory” which can be recalled, for example, for subduction initiation (e.g., Crameri et al., 2020; Gurnis et al., 2000) or supercontinental breakup (e.g., Dang et al., 2020). Given that continental plates record geology for ∼10 times longer than the more rapidly recycled oceanic lithosphere, memory effects may thus be most important for continents.…”

Section: Introductionmentioning

confidence: 99%

On the Role of Rheological Memory for Convection‐Driven Plate Reorganizations

Fuchs

Becker

2022

Geophysical Research Letters

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Understanding the temporal variability of plate tectonics is key to unraveling how mantle convection transports heat, and one critical factor for the formation and evolution of plate boundaries is rheological “memory,” that is, the persistence of weak zones. Here, we analyze the impact of such damage memory in global, oceanic‐lithosphere‐only models of visco‐plastic mantle convection. Self‐consistently‐formed weak zones are found to be reactivated in distinct ways, and convection preferentially selects such damaged zones for new plate boundaries. Reactivation of damage zones increases the frequency of plate reorganizations, and hence reduces the dominant periods of surface heat loss. The inheritance of distributed lithospheric damage thus dominates global surface dynamics over any local boundary stabilizing effects of weakening. In nature, progressive generation of weak zones may thus counteract and perhaps overcome any effects of reduced convective vigor throughout planetary cooling, with implications for the frequency of orogeny and convective transport throughout Wilson cycles.

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“…past subduction zones, orogens, shear zones), the physico-chemical interaction between upwellings and lithospheric architecture, and the large-scale stress field. Pre-existing zones of weakness play a critical role in combination with mantle upwellings during continental breakup 39 and studies of interactions between asthenospheric flow and craton geometry suggest that sharp craton margins, such as that imaged around the CASZ, are more resistant to deformation and erosion than gradual margins (e.g. Rehoboth Block) 40 .…”

Section: Implications For the Evolution Of Cratonic Lithospherementioning

confidence: 99%

Thermochemical structure and evolution of cratonic lithosphere in central and southern Africa

Afonso¹,

Mansour²,

Griffin³

et al. 2022

Preprint

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The thermochemical structure of the subcontinental mantle holds crucial information on its origin and evolution that can inform energy and mineral exploration strategies, natural haz-ard mitigation and evolutionary models of the Earth1−4. However, imaging the fine-scale thermochemical structure of continental lithosphere remains a major challenge. Here we combine multiple land and satellite datasets via thermodynamically-constrained inversions to obtain a high-resolution thermochemical model of central and southern Africa. Results reveal diverse structures and compositions for cratons, indicating distinct evolutions and responses to geodynamic processes. While much of the Kaapvaal lithosphere retained its cra-tonic features, the western Angolan-Kasai shield and the Rehoboth block have lost their cra-tonic keels. The lithosphere of the Congo Craton has been affected by metasomatism, increas-ing its density and inducing its conspicuous low-topography, geoid and magnetic anomalies. Our results reconcile mantle structure with the causes and location of volcanism within and around the Tanzanian Craton, whereas the absence of volcanism towards the north is the result of local asthenospheric downwellings, not to a previously-proposed lithospheric root connecting with the Congo Craton. Our study offers greatly improved integration of man-tle structure, magmatism and the evolution and destruction of cratonic lithosphere and lays the groundwork for new evolutionary models and exploration frameworks for the Earth and other terrestrial planets.

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Weak orogenic lithosphere guides the pattern of plume-triggered supercontinent break-up

Cited by 31 publications

References 101 publications

Mantle plumes and their role in Earth processes

Mantle plumes and their role in Earth processes

On the Role of Rheological Memory for Convection‐Driven Plate Reorganizations

Thermochemical structure and evolution of cratonic lithosphere in central and southern Africa

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